This invention relates generally, as indicated, to a reflector system, and more particularly, to a reflector system which provides for relatively efficient light collection and focalization upon a relatively tight target or light receiving area.
It is generally known from U.S. Pat. No. 4,241,382 to provide an illuminator in the form of a light bulb including a combination of ellipsoidal and spherical mirrors which together direct the light emitted from a filament or other light source through a small optical window located at the rear of a fiber optics coupler integral with the bulb envelope into a fiber optics light pipe or the like. To facilitate trapping of the light in the optical fibers, the light may be caused to emerge from the optical window at angles equal to or less than the critical angles of the fibers.
Also, it is generally known from such U.S. patent to provide a multilayer interference film on the ellipsoidal reflector which is highly reflective of visible light and highly transmissive of heat or infra-red radiation to allow most heat to escape into the surroundings instead of being focused onto the fiber optics ends.
While such an illuminator is fairly efficient in directing the light generated by a filament into the end of an attached fiber optics light pipe within the limitations of losses incurred by non-ideal optical components, there is a continuing need for greater efficiencies in light collection and focalization on a limited target as in the case of channeling light into a fiber optics cable or the like.
In most lighting systems, it is desirable to extract the highest possible light output in lumens per watt of energy input while achieving an adequate amount of intensity. In the usual case, little effort is made to efficiently collect the existing light. Instead, a more intensive light source is utilized than would otherwise be required to make up for the inefficiencies in the light collector. However, there are many applications in which this is not desirable or acceptable such as when light is being channeled into an acrylic (plastic) fiber optics cable because of the damage that may result from the excess heat generated by an overly bright light source.
A relatively efficient light source is generally no more than 50% efficient. That is, for every watt of energy in the optical range generated, another watt of non-optical energy is simultaneously generated. Arc lamps and metal-halide lamps are in the higher range of optical efficiencies, whereas incandescent lamps are in the lowest range. Accordingly, any increase in the wattage of a lamp to increase its brightness will proportionately increase the existing infra-red energy which could cause heat problems.
Another objection to many illuminators including that shown in the aforementioned U.S. Pat. No. 4,241,382 is that they require an elongated construction which in many cases does not readily lend itself to an acceptable compact package shape.